Levy teaches an adjustable framing tool with indicia but contains no reference tables for set up. Further, Levy doesn't provide a side bracket with a generous surface area, but instead has narrow ruler edges which can easily slide off the edge of the board.
McLeod also teaches an adjustable framing tool with indicia plus reference tables. However, the framing square is not slotted to receive the bolts and would therefore easily loose it's setting. Further, the adjustable sliding scale is thin and will slide off the edge of the board during use.
Marty teaches an adjustable framing tool which provides a generous surface to contact both the front face and the narrow side of the board and provides marks and indicia to help set up the tool for stringer marking. However, Marty lacks any marks, indicia or reference tables to set the tool for rafter line marking.
A step and rafter tool is presented herein for marking cut lines on a board to be used as a step stringer or roof rafter. This too provides all the elements of the related art mentioned above and more. The tool comprises a framing square with long slots running down the center of each leg, an angle bracket with long slots running down the center of one flange, and two clamping units which can clamp the angle bracket against the framing square to hold them in a fixed face to face position relative to one another so that the user can use the tool to make cut lines at repeatable angles on a board. The angle bracket provides a broad surface for sliding the toll against the narrow edge of a board.
On one face of the framing square are a reference table and marks which are laid off in inches and fractions of a inches and labeled with numbers indication inches. The reference table gives inches of ‘rise’ for a step when the floor-to-floor height in inches is known. If the user knows the tread depth, toe board thickness, and overhang, then the ‘run’ can be easily determined. The user now sets the angle bracket to correspond to the ‘rise’ and ‘run’ and tightens the clamps. The tool is now ready to mark all the step cut lines.
On the opposite face of the framing square are pitch guidelines and a handy reference table to help a user figure rafter lengths given rafter type and the roof pitch, and ‘run’ lengths. If the desired roof pitch is known, the user simply sets the lower edge of the angle bracket to correspond to the guidelines marked on the legs of the framing square and tightens the clamps. The tool is now ready to use to mark all rafter cuts including the end cuts and the notch call the ‘bird's mouth’ which provides a seat wear the rafter is connected to the outer wall of the building.
In order to figure the length of a rafter, the user needs the rafter type, the roof pitch, and ‘run’ length (or horizontal distance covered by the rafter). Given these three pieces of data, the user finds in the reference table a ‘multiplier’ corresponding to the rafter type and roof pitch. The desired rafter length (in inches) is simply the product of the ‘run’ length (in inches) and the ‘multiplier’.